Glutathione reductase (GR; EC 1.6.4.2) is a key NADPH-dependent flavo-protein oxidoreductase which can catalyze the oxidized glutathione (GSSG) to reduced glutathione (GSH) to protect plant cells from oxidative damage induced by Reactive oxygen species (ROS) burst. To investigate the biochemical characteristics and functional divergence of Populus GR family, three GR genes (PtGR1.1/1.2/2) were cloned from Populus trichocarpa and their biochemical characteristics were analyzed in this study. All the three genes were expressed in root, stem, leaf and bud, and the expression of PtGR genes were general upregulated under salicylic acid and alamethicin treatment. PtGR1.1 and PtGR1.2 were localized in cytoplasm, while PtGR2 was in chloroplast. The three PtGR proteins showed different enzymatic activities, apparent kinetic characteristic and thermal stability profiles. However, they have similar bivalent metal ions (Cu2+, Cd2+, Zn2+ and Pb2+) sensitivity and optimum pH profiles. Our study sheds light on a comprehensive information of glutathione reductase family in P. trichocarpa, and proved PtGR genes play critical roles when suffering different stresses.

中文翻译：

---

毛果杨谷胱甘肽还原酶家族的鉴定和生化表征

谷胱甘肽还原酶 (GR; EC 1.6.4.2) 是一种关键的 NADPH 依赖性黄素蛋白氧化还原酶，可将氧化型谷胱甘肽 (GSSG) 催化为还原型谷胱甘肽 (GSH)，从而保护植物细胞免受活性氧 (ROS) 诱导的氧化损伤爆裂。为了研究杨树GR家族的生化特征和功能差异，本研究从毛果杨中克隆了三个GR基因（PtGR1.1/1.2/2）并分析了它们的生化特征。3个基因在根、茎、叶和芽中均有表达，水杨酸和阿拉霉素处理下PtGR基因的表达普遍上调。PtGR1.1和PtGR1.2定位于细胞质中，而PtGR2定位于叶绿体中。三种 PtGR 蛋白表现出不同的酶活性，表观动力学特性和热稳定性曲线。然而，它们具有相似的二价金属离子（Cu2+、Cd2+、Zn2+ 和 Pb2+）敏感性和最佳 pH 曲线。我们的研究揭示了 P. trichocarpa 中谷胱甘肽还原酶家族的全面信息，并证明 PtGR 基因在遭受不同压力时起着关键作用。